"Pearl says she only takes pictures with celebrities," Piven tells me. "And then she got a picture with Selena Gomez and she told it was because it was her 'destiny.' That's what she told me—her 'destiny!' "

So Piven is working overtime to prove himself to the little one, including starring in Spy Kids 4, director Robert Rodriguez's fourth installment of his hit family franchise (in theaters Aug. 19). Piven plays multiple characters. "All I'm doing right now with my career is trying to impress my niece," he said. "I tried buying American Girl dolls. It worked in the moment, but then it wears off."

Even working with Miley Cyrus in the upcoming So Undercover hasn't helped. He told her once he played drums when Cyrus sang at their wrap party. "Without missing a beat, Pearl goes, 'She's a much better singer than you are a drummer,'" Piven said.

Pearl sounds pretty cool to us.

As for the Entourage flick (if for some reason you haven't heard, a movie is already being planned for the hit HBO series after it ends this season), Piven said it makes sense, especially for his television alter ego Ari Gold. "Ari walks away with this conundrum," he said. "I can't tell you what it is, but I think it's one we've all faced and it's kind of a perfect way to end—or the perfect way to segue into a movie."